US President Donald Trump resumed a full-throated attack on James Comey, hours before the FBI director he fired in May will appear in a network television interview ahead of the release of a book that describes the president in unfavourable terms.

“I never asked Comey for Personal Loyalty. I hardly even knew this guy. Just another of his many lies. His ‘memos’ are self serving and FAKE!” Trump said on Twitter early Sunday, one of five Comey-related tweets of the morning.

“Slippery James Comey, a man who always ends up badly and out of whack (he is not smart!), will go down as the WORST FBI Director in history, by far!” Trump also said in what so far has been the final tweet.

Trump’s tweet storm comes ahead of a highly anticipated interview with Comey on ABC News to be broadcast on Sunday night. Comey will discuss his memoir, A Higher Loyalty: Truth, Lies and Leadership, which is scheduled for release on Tuesday.

Unbelievably, James Comey states that Polls, where Crooked Hillary was leading, were a factor in the handling (stupidly) of the Clinton Email probe. In other words, he was making decisions based on the fact that he thought she was going to win, and he wanted a job. Slimeball!

The big questions in Comey’s badly reviewed book aren’t answered like, how come he gave up Classified Information (jail), why did he lie to Congress (jail), why did the DNC refuse to give Server to the FBI (why didn’t they TAKE it), why the phony memos, McCabe’s $700,000 & more?

Comey, who ran the FBI for almost four years, portrays the president in the book as a liar, dumb and rude, and he compares elements of Trump’s behaviour to that of a mafia boss.

The thought of having dinner alone with Trump at the White House made Comey “deeply uncomfortable,” he writes in the book, because he feared that the president wanted to compromise the FBI’s integrity and independence and was waging “an effort to establish a patronage relationship” with him.

The Republican National Committee has started an effort to discredit Comey on social media, in digital advertising, and through a website, lyincomey.com, ahead of the release of the book.

White House press secretary Sarah Huckabee Sanders said on Friday that Comey has a “credibility problem” and that firing him will go down as one of Trump’s greatest achievements.

On Sunday, on ABC’s This Week, she said it was clear that Comey was a “leaker” by his own admission and “there is such a huge bipartisan consensus that James Comey doesn’t have credibility and shouldn’t have been leading the FBI any longer”.

House Speaker Paul Ryan said on Sunday that Comey is a man of integrity “as far as I know,” while adding that “I don’t know the guy”.

Asked whether Comey is someone he would describe as a slime ball – a term Trump has used twice in tweets this week – Ryan said in an interview broadcast Sunday on NBC’s Meet the Press that “I don’t speak like that. I don’t use words like that.”